One of the undesirable side effects accompanying transthoracic defibrillation is the erythematous circles left on the skin following application of the pulse of defibrillating current. Similar rings often appear on the ventricles when direct-heart defibrillation is accomplished. These rings are produced by the high current density that occurs at the periphery of the electrodes. This high current density causes a local temperature rise which produces thermal injury to the subjacent tissues. By the use of a conducting pad of the proper resistivity and dimensions placed over the electrode surface, it is possible to reduce the peripheral current density and therefore minimize the heating that occurs at the periphery of defibrillating electrodes. It is the objective of this proposal to make a theoretical analysis of this phenomenon and to create conducting pads of the appropriate resistivity and dimensions to eliminate the undesirable tissue response to defibrillating current.